The efficient utilization of different biomass has attracted increasing attention due to the diminishing resources of fossil fuels as well as global warming warnings caused by greenhouse gas emissions. This interest has prompted work towards techniques for converting biomass to valuable products, such as biofuels, chemicals, and other biomaterials.
Wood, being one of the most abundant lignocellulosic materials available on the planet, to date, has mainly been utilized for the production of paper products from cellulose and as a raw material for building products.
Other lignocellulosic biomass materials, such as non-wood sources, e.g., sugar cane, switchgrass, and the like, as well as agricultural waste, forest residuals, and recovered lignocellulosic fiber, are other readily available sources of biomass that include components that can be recovered and converted to valuable products, such as biofuels, chemicals, and biomaterials.
The main components of lignocellulosic biomass materials are cellulose, lignin, hemicellulose, and extractives.
The lignin component is a vastly underutilized natural polymer. Lignin generated by the paper industry is typically utilized as a fuel in a chemical pulping process. Other uses of lignin include as a stabilizer for plastics and rubber, as well as in the formulation of dispersants, adhesives, and surfactants.
Ionic liquids are liquids that contain essentially only ions. Some ionic liquids are in a dynamic equilibrium where at any time more than 99.99% of the liquid is made up of ionic rather than molecular species. In the broad sense, the term “ionic liquid” includes all molten salts; however, the term “ionic liquid” is commonly used for salts whose melting point is relatively low (e.g., below 100° C.). In particular, the salts that are liquid at room temperature are often referred to as room temperature ionic liquids, or RTILs. Ionic liquids are generally considered to be environmentally friendly solvents in the sense that they are not volatile at normal operating temperatures. This is viewed favorably in light of the growing realization of the need to protect the environment. Furthermore, some ionic liquids have a chemical composition that is considered “green”.
Although using ionic liquids as solvents to dissolve lignocellulosic biomass materials has been reported, development of practical utilizations of the solubility of lignocellulosic biomass material in ionic liquids is in its infancy.